<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      margin: 0;
      font-size: 0;
    }

    #main {
      width: 100vw;
      height: 100vh;
      background-color:#4eabbb;
      /* display: block; */
      /* vertical-align: top; */
    }
  </style>
</head>
<body>

  <canvas id="main"></canvas>

</body>
</html>